Seamounts in the southeastern Pacific Ocean and biodiversity on Juan Fernandez seamounts, Chile

Abstract

ABSTRACT. Seamounts are vulnerable marine ecosystems. In Chile, information on these ecosystems is quite scarce; thus, a compilation of information on their geographical distribution and biodiversity is presented herein. A total of 118 seamounts distributed in the Chilean EEZ are identified and characterized. Additionally, an in situ assessment was carried out on the Juan Fernandez seamounts 1 and 2 (JF1 and JF2), which were also oceanographically characterized. Phytoplankton, zooplankton, and marine invertebrate samples were collected and an exploratory fishing survey was executed using different gears. According to the bibliographical review, a total of 82 species have been collected on the JF1 and JF2 seamounts, highlighting findings of black coral species caught in lobster traps at the Juan Fernandez Archipelago. Submarine images of the marine substrate at JF1 and JF2 reveal characteristics attributable to the impact of bottom dredges, coinciding with the information obtained from the trawling fleet. The fishing activity was carried out primarily at JF2 (4,667 km of trawling). The monthly fishing effort increased considerably in 2002, 2003, and 2005, reaching values above 500 km of trawling and, thus, modifying the spatial structure of the resource aggregates on the JF2 seamount.

Unexplored diversity of the mesophotic echinoderm fauna of the Easter Island ecoregion

“…Family Asterodiscididae Rowe 1977 This family comprises four genera with wide tropical and sub-tropical Indo-Pacific distributions (Rowe 1977(Rowe , 1985; however non have been reported for the southeast Pacific (Marsh 1974;Parin et al 1997;Yanez et al 2009). Therefore, this report is the first for this family in the EIE.…”

Local and remote physical processes driving variability of the planktonic system in the Juan Fernández Archipelago: A multidisciplinary framework providing conservation insights

“…In the laboratory, zooplankton samples were categorized according to high-level taxonomic groups: Euphausiids, Chaetognaths, Amphipods, Polychaetes, Ostracods, Decapods, Copepods, Appendicularia, Siphonophores, Cephalopods and Salps. For each quadrant, one sample from coastal and offshore sectors was selected, and zooplankton was identified to the highest possible taxonomic level following identification guides (Antezana, Aguirre, & Bustamante, 1976;Brinton & Wyllie, 1976;Galloti, 2013) and zooplankton literature around JFA (Mujica & Pavez, 2008;Palma, 1985;Yañez et al, 2009). This information was used to identify the gender composition of scattering layers (see below) and to estimate the direct relative abundance of different groups.…”

“…In order to relate physical attributes of the water column and planktonic data, it is necessary to obtain fine-scale resolution data aligned in the same spatial and temporal scales. Available data on community structure of zooplankton around RC Island have been obtained sporadically from net-collection methods (Frederick, Escribano, Morales, Hormazábal, & Medellín-Mora, 2018;Mujica & Pavez, 2008;Palma, 1985;Yañez et al, 2009), thus providing discrete low-resolution information. To improve the spatial resolution of zooplankton studies, acoustics methods are increasingly popular, providing continuous fine-scale resolution data (Smeti et al, 2015).…”

Distribution and biodiversity patterns of hyperiid amphipods across the coastal-offshore gradient of the sub-tropical Southeast Pacific

“…Strong effects of the physical-chemical and biological gradients on the spatial distribution and structure of pelagic communities have been shown in micro-organisms (Masquelier and Vaulot 2008), epipelagic siphonophores (Palma and Silva 2006), and zooplankton size-classes (González et al 2019). For some groups, the species and their distribution along this gradient have been described, such as for copepods within the HCS (Escribano et al 2007) and the CTZ (Morales et al 2010) although this group is poorly studied in the South Pacific central gyre (Yáñez et al 2009;Von Dassow and Collado-Fabbri 2014).…”